Drop interrupted workers from live agents

CHANGELOG.md

@@ -19,6 +19,11 @@ parallel copies under `docs/` or `scripts/notes/`. At cut time: rename
   the operator answers.
 - The `full_shell` overlay mode is removed; every overlay is inset.
 
+### Fixed
+
+- Interrupted workers linger on the agents strip for 4s then drop, instead of
+  staying in the live list while leftover tools finish.
+
 ## [0.3.7] - 2026-08-27
 
 ### Fixed

docs/TUI.md

@@ -220,9 +220,10 @@ status / current tool) — Amp/Codex-style lanes without a FLEET header board:
 
 `formatChromeZones` → `formatAgentsPanel` owns that paint. Geometry stays
 stack-only (`layoutMode: "stack"`, `railWidth: 0`); the zone max is
-`AGENTS_PANEL_MAX_VISIBLE + 1` (lanes plus a trailing `+N more`). Terminal
-lanes (done / failed / cancelled) linger for `AGENTS_PANEL_LINGER_MS` (4s)
-after `finishedAt`, then drop. Product-host sticky poll uses
+`AGENTS_PANEL_MAX_VISIBLE + 1` (lanes plus a trailing `+N more`). Finished
+lanes (done / failed / cancelled / interrupted) linger for
+`AGENTS_PANEL_LINGER_MS` (4s) after `finishedAt`, then drop. Product-host sticky
+poll uses
 `agentsChromeNeedsSticky` so clocks and linger stay fresh; while sticky is
 needed it **does not** call `bridge.syncAgentProgress` — chrome owns the live
 clocks.

src/inference-error-message.ts

@@ -20,9 +20,11 @@ import {
   type InferenceErrorLike,
 } from "./inference-gateway-error.js";
 
+/** Committed auth death — do not claim a refresh is in flight. */
+export const CREDENTIAL_FAILURE_USER_MESSAGE = "Authentication failed — log in again.";
+
 const FRIENDLY_BY_CATEGORY: Record<string, string> = {
-  // Committed auth death — do not claim a refresh is in flight.
-  credential_failure: "Authentication failed — log in again.",
+  credential_failure: CREDENTIAL_FAILURE_USER_MESSAGE,
   quota_exhausted: "Quota exhausted — usage limit reached.",
   context_overflow:
     "Context window full — compaction could not keep up. Try /clear to start fresh.",

src/subagent/agent-fleet.test.ts

@@ -15,6 +15,8 @@ import {
 } from "./lifecycle-tools.js";
 import { createSubAgentSessionStore } from "./session-store.js";
 import { createPermissionGate } from "../permission/gate.js";
+import { agentLaneIsLive, fleetProgress } from "../tui/agent-progress.js";
+import { AGENTS_PANEL_LINGER_MS, formatAgentsPanel } from "../tui/chrome-state.js";
 import { forcedStopReport } from "./stop-policy.js";
 import type { RunSubAgentParams, RunSubAgentResult } from "./types.js";
 
@@ -921,6 +923,48 @@ describe("list_agents", () => {
     expect(parsed.agents[0]!.lifecycle).toBe("pending_init");
     gate.resolve({ report: "done" });
   });
+
+  test("interrupt_agent leaves the strip after the linger window", async () => {
+    const gate = deferred<RunSubAgentResult>();
+    const deps = makeDeps(async (params) => {
+      params.onAgentReady?.({
+        close: async () => {},
+        interrupt: () => {},
+        followup: async () => "",
+        deliver: () => {},
+      });
+      return gate.promise;
+    });
+    const spawn = createSpawnAgentTool(deps);
+    const interrupt = createInterruptAgentTool({
+      sessions: deps.sessions,
+      fleetRecords: deps.fleetRecords,
+    });
+    const spawned = await callTool(spawn, {
+      description: "looping",
+      prompt: "do it",
+      intent: "explore",
+    });
+    const id = spawned.agent_id as string;
+    await new Promise((resolve) => setTimeout(resolve, 20));
+    if (interrupt.kind !== "full") throw new Error("expected full tool");
+    await interrupt.handler(
+      { id: "int-strip", name: "interrupt_agent", arguments: { target: id } },
+      new AbortController().signal,
+    );
+    const agents = deps.sessions.list();
+    const session = agents[0]!;
+    expect(session.status).toBe("running");
+    expect(session.lifecycleStatus).toBe("interrupted");
+    expect(agentLaneIsLive(session)).toBe(false);
+    const finishedAt = session.finishedAt!;
+    expect(finishedAt).toBeNumber();
+    const inside = finishedAt + 1_000;
+    expect(fleetProgress(agents, inside).running).toBe(0);
+    expect(formatAgentsPanel(agents, undefined, inside)?.[0]?.status).toBe("interrupted");
+    expect(formatAgentsPanel(agents, undefined, finishedAt + AGENTS_PANEL_LINGER_MS)).toBeNull();
+    gate.resolve({ report: "done", interrupted: true });
+  });
 });
 
 describe("spawn_agent parity with task", () => {

src/subagent/agent-fleet.ts

@@ -546,14 +546,15 @@ export function createSpawnAgentTool(deps: AgentFleetDeps): AgentTool {
       const startedAt = Date.now();
       let settlement: Readonly<SubAgentRunSettlement> | undefined;
       let endFinalized = false;
+      let runInterrupted = false;
       const finalizeEnd = (setupFailed = false): void => {
         if (endFinalized) return;
         endFinalized = true;
         const terminalSession = deps.sessions.get(session.id);
         const status =
           terminalSession?.status === "cancelled"
             ? "cancelled"
-            : terminalSession?.lifecycleStatus === "interrupted"
+            : runInterrupted || terminalSession?.lifecycleStatus === "interrupted"
               ? "interrupted"
               : (terminalSession?.status ?? "completed");
         captureSubagentEnd(telemetry, {
@@ -731,14 +732,16 @@ export function createSpawnAgentTool(deps: AgentFleetDeps): AgentTool {
       deps
         .run(params)
         .then((result) => {
-          // interrupt_agent already flipped this session to "interrupted"
-          // synchronously (session-store.interruptOne) — do not let the
-          // settling promise's normal bookkeeping overwrite that with a
-          // "completed" status. Still terminalize fleetRecords so a waiter
-          // that never saw interrupt_agent (or raced it) cannot hang.
+          // interrupt_agent / send_input already flipped this session
+          // synchronously (session-store.interruptOne / sendInputOne) — do not
+          // let the settling promise's normal bookkeeping overwrite that with
+          // a "completed" status, and do not re-stamp the interrupt either: a
+          // follow-up turn may already be live on this lane. Still terminalize
+          // fleetRecords so a waiter that never saw interrupt_agent (or raced
+          // it) cannot hang.
           if (result.interrupted === true) {
             keepWorktreeAlive = true;
-            deps.sessions.interruptOne(session.id);
+            runInterrupted = true;
             deps.fleetRecords.interrupt(session.id, result.report);
             return;
           }

src/subagent/lifecycle-tools.test.ts

@@ -330,7 +330,8 @@ describe("send_input", () => {
     expect(result).toEqual({ agent_id: worker.id, status: "interrupted" });
     expect(interrupted).toBe(true);
     expect(followupStarted).toBe(true);
-    expect(sessions.get(worker.id)?.lifecycleStatus).toBe("interrupted");
+    expect(sessions.get(worker.id)?.lifecycleStatus).toBe("running");
+    expect(sessions.get(worker.id)?.finishedAt).toBeUndefined();
 
     const missing = sessions.start({
       description: "no-followup",

src/subagent/session-store.test.ts

@@ -2,6 +2,8 @@ import { describe, expect, test } from "bun:test";
 
 import { createSubAgentSessionStore } from "./session-store.js";
 import { forcedStopReport } from "./stop-policy.js";
+import { agentLaneIsLive, fleetProgress } from "../tui/agent-progress.js";
+import { formatAgentsPanel } from "../tui/chrome-state.js";
 
 import type { ReactorEmittedEvent } from "@intx/inference";
 
@@ -519,3 +521,132 @@ describe("CL-6943 reusable worker sessions", () => {
     expect(store.get(retained.id)).toBeUndefined();
   });
 });
+
+describe("interrupt stamps finishedAt once", () => {
+  test("interruptOne sets finishedAt, keeps status running, and preserves tools", () => {
+    let t = 1000;
+    const store = createSubAgentSessionStore({
+      now: () => t,
+      createId: () => "s-int",
+    });
+    const session = store.start({
+      description: "looping",
+      agentId: "explorer",
+      brief: "b",
+      retained: true,
+    });
+    store.markRunning(session.id);
+    store.appendEvent(session.id, startCall(1, "call-1", "run_shell"));
+    store.registerInterrupt(session.id, () => {});
+
+    t = 2000;
+    expect(store.interruptOne(session.id).ok).toBe(true);
+    const after = store.get(session.id);
+    expect(after?.status).toBe("running");
+    expect(after?.lifecycleStatus).toBe("interrupted");
+    expect(after?.finishedAt).toBe(2000);
+    expect(after?.outstandingTools).toHaveLength(1);
+    expect(after?.currentToolName).toBe("run_shell");
+
+    t = 3500;
+    expect(store.interruptOne(session.id).ok).toBe(true);
+    expect(store.get(session.id)?.finishedAt).toBe(2000);
+    expect(store.get(session.id)?.status).toBe("running");
+    expect(store.get(session.id)?.outstandingTools).toHaveLength(1);
+  });
+
+  test("sendInputOne interrupt starts a live follow-up turn and keeps tools", async () => {
+    let t = 1000;
+    let finish: (reply: string) => void = () => {};
+    const store = createSubAgentSessionStore({
+      now: () => t,
+      createId: () => "s-send",
+    });
+    const session = store.start({
+      description: "looping",
+      agentId: "explorer",
+      brief: "b",
+      retained: true,
+    });
+    store.markRunning(session.id);
+    store.appendEvent(session.id, startCall(1, "call-1", "run_shell"));
+    store.registerInterrupt(session.id, () => {});
+    store.registerFollowup(
+      session.id,
+      () =>
+        new Promise<string>((resolve) => {
+          finish = resolve;
+        }),
+    );
+
+    t = 2500;
+    const outcome = store.sendInputOne(session.id, "stop that", { interrupt: true });
+    expect(outcome).toEqual({ ok: true, status: "interrupted" });
+    const after = store.get(session.id);
+    expect(after?.status).toBe("running");
+    expect(after?.lifecycleStatus).toBe("running");
+    expect(after?.finishedAt).toBeUndefined();
+    expect(after?.outstandingTools).toHaveLength(1);
+
+    t = 4000;
+    expect(store.interruptOne(session.id).ok).toBe(true);
+    expect(store.get(session.id)?.finishedAt).toBe(4000);
+
+    t = 5000;
+    finish("later");
+    await new Promise((resolve) => setTimeout(resolve, 0));
+    expect(store.get(session.id)?.status).toBe("done");
+    expect(store.get(session.id)?.lifecycleStatus).toBe("completed");
+    expect(store.get(session.id)?.finishedAt).toBe(5000);
+  });
+
+  test("a follow-up turn keeps the lane live past the linger window until it completes", async () => {
+    let t = 1000;
+    let finish: (reply: string) => void = () => {};
+    const store = createSubAgentSessionStore({
+      now: () => t,
+      createId: () => "s-followup",
+    });
+    const session = store.start({
+      description: "looping",
+      agentId: "explorer",
+      brief: "b",
+      retained: true,
+    });
+    store.markRunning(session.id);
+    store.registerInterrupt(session.id, () => {});
+    store.registerFollowup(
+      session.id,
+      () =>
+        new Promise<string>((resolve) => {
+          finish = resolve;
+        }),
+    );
+
+    t = 2000;
+    expect(store.interruptOne(session.id).ok).toBe(true);
+    expect(store.get(session.id)?.finishedAt).toBe(2000);
+
+    t = 3000;
+    const pending = store.followupOne(session.id, "keep going");
+
+    t = 11_000;
+    store.appendEvent(session.id, startCall(1, "call-1", "run_shell"));
+    const live = store.list();
+    expect(live[0]?.lifecycleStatus).toBe("running");
+    expect(live[0]?.finishedAt).toBeUndefined();
+    expect(agentLaneIsLive(live[0]!)).toBe(true);
+    expect(formatAgentsPanel(live, undefined, t)?.[0]?.status).toBe("running");
+    expect(fleetProgress(live, t).running).toBe(1);
+
+    t = 12_000;
+    finish("done");
+    expect(await pending).toEqual({ ok: true, reply: "done" });
+    const terminal = store.list();
+    expect(terminal[0]?.status).toBe("done");
+    expect(terminal[0]?.lifecycleStatus).toBe("completed");
+    expect(terminal[0]?.finishedAt).toBe(12_000);
+    expect(agentLaneIsLive(terminal[0]!)).toBe(false);
+    expect(fleetProgress(terminal, t).running).toBe(0);
+  });
+});

src/subagent/session-store.ts

@@ -79,6 +79,9 @@ export interface SubAgentSession {
   // start/end, a status change). Distinct from startedAt so the strip can
   // tell a worker mid-turn from one that has gone silent.
   lastActivityAt: number;
+  // Clock the live turn ended (complete/fail/cancel, and interrupt while TUI
+  // status may still be "running"). Drives chrome linger; leftover tools may
+  // still be outstanding after this stamp.
   finishedAt?: number;
   report?: string;
   error?: string;
@@ -594,6 +597,23 @@ export function createSubAgentSessionStore(
     notify();
   };
 
+  // A follow-up turn takes the lane back over: the worker is live again, so
+  // the interrupt's linger stamp must not outlive the new turn. Completion
+  // re-stamps through the caller's own mutate; a rejected turn restores the
+  // addressable state it started from so followup_task can retry.
+  const beginFollowupTurn = (id: string): void => {
+    mutate(id, (s) => {
+      s.lifecycleStatus = "running";
+      delete s.finishedAt;
+    });
+  };
+  const endFollowupTurn = (id: string, lifecycleStatus: AgentLifecycleStatus): void => {
+    mutate(id, (s) => {
+      s.lifecycleStatus = lifecycleStatus;
+      s.finishedAt = now();
+    });
+  };
+
   return {
     list(): readonly SubAgentSession[] {
       return [...sessions.values()].map(snapshotOf);
@@ -972,9 +992,7 @@ export function createSubAgentSessionStore(
           return { ok: false, status: session.lifecycleStatus };
         }
         interrupt();
-        mutate(id, (s) => {
-          s.lifecycleStatus = "interrupted";
-        });
+        beginFollowupTurn(id);
         void followup(message)
           .then((reply) => {
             const still = sessions.get(id);
@@ -990,6 +1008,7 @@ export function createSubAgentSessionStore(
             pruneRetained();
           })
           .catch((err: unknown) => {
+            endFollowupTurn(id, "interrupted");
             log.error("send_input followup failed for {id}: {error}", {
               id,
               error: err instanceof Error ? err.message : String(err),
@@ -1014,6 +1033,7 @@ export function createSubAgentSessionStore(
       interrupt();
       mutate(id, (s) => {
         s.lifecycleStatus = "interrupted";
+        s.finishedAt = s.finishedAt ?? now();
       });
       pruneRetained();
       return { ok: true };
@@ -1041,7 +1061,15 @@ export function createSubAgentSessionStore(
       }
       const followup = followupHandles.get(id);
       if (followup === undefined) return { ok: false, status: session.lifecycleStatus };
-      const reply = await followup(message);
+      const priorLifecycle = session.lifecycleStatus;
+      beginFollowupTurn(id);
+      let reply: string;
+      try {
+        reply = await followup(message);
+      } catch (err) {
+        endFollowupTurn(id, priorLifecycle);
+        throw err;
+      }
       mutate(id, (s) => {
         s.status = "done";
         s.lifecycleStatus = "completed";

src/subagent/spawn-agent-worktree.test.ts

@@ -347,6 +347,8 @@ describe("spawn_agent worktree isolation", () => {
     const content = typeof spawned.content === "string" ? spawned.content : "";
     const agentId = (JSON.parse(content) as { agent_id: string }).agent_id;
 
+    await waitFor(() => sessions.get(agentId)?.lifecycleStatus === "running");
+    expect(sessions.interruptOne(agentId).ok).toBe(true);
     settle.resolve({
       report: "## Summary\nStopped.\n## Findings\npartial\n## Blockers\ninterrupted\n## Paths\n",
       stopReason: "cancelled",